The focus of this study is to determine the role of Type IX collagen in establishing the three dimensional arrangement of collagen fibrils in bone. The HVEM, and animated tilt series photos, are being used to examine the differences in collagen fibril arrangement between normal and mutant animals. We have found that we can observe the directionality and network structure of collagen in thick sections by HVEM but not by conventional 100 kV TEM.. This is an ongoing study. .